In the past few years, the killing and capture of many Al-Qaeda leaders has left the terrorist organization wounded — but by no means dead. And they intend to prove it. On a dark summer night, two Chechen mercenaries emerge from the waters off Nantucket to kill a high-value target, the former president of the United States, Jake Cazalet. Unfortunately for them, Cazalet has guests with him, including black ops specialist Sean Dillon and his colleague,...